Related Experiment Video

Updated: Sep 17, 2025

Expression, Detergent Solubilization, and Purification of a Membrane Transporter, the MexB Multidrug Resistance Protein
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Expression, Detergent Solubilization, and Purification of a Membrane Transporter, the MexB Multidrug Resistance Protein

Published on: December 3, 2010

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Structural and functional insights of AmpG in muropeptide transport and multiple β-lactam antibiotics resistance

Nienping Chang1, Hoyoung Kim1,2, Uijin Kim1

  • 1Department of Systems Biology and Division of Life Sciences, Yonsei University, 50 Yonsei-ro, Seoul, Republic of Korea.

Nature Communications
|July 2, 2025
PubMed

Insights

Anhydromuropeptide permease (AmpG) is crucial for bacterial resistance. Understanding its structure and transport mechanism is key to developing new antibiotic adjuvants to combat resistant bacteria.

Area of Science:

  • Structural biology
  • Microbiology
  • Biochemistry

Background:

  • Anhydromuropeptide permease (AmpG) is an inner membrane transporter in Gram-negative bacteria.
  • AmpG plays a role in peptidoglycan recycling and beta-lactamase induction.
  • Targeting AmpG offers a strategy to develop antibiotic adjuvants against resistant bacteria.

Purpose of the Study:

  • To determine the tertiary structure of AmpG.
  • To elucidate the muropeptide transport mechanism of AmpG.
  • To provide a structural basis for developing AmpG-targeting inhibitors.

Main Methods:

  • Cryo-electron microscopy (cryo-EM) to obtain high-resolution structures.
  • Functional analysis to assess AmpG activity.
  • Molecular dynamics (MD) simulations to study protein behavior.

Main Results:

  • Four cryo-EM structures of AmpG were determined: apo-inward, apo-outward, inward-occluded, and outward states.
  • Key structural features like motif A, substrate-binding pocket, and protonation sites were identified.
  • A potential muropeptide transport mechanism for AmpG was proposed.

Conclusions:

  • The determined structures provide unprecedented insights into AmpG's conformation and function.
  • Understanding AmpG's structure and mechanism is essential for designing novel antibiotic adjuvants.
  • This research lays the groundwork for developing new strategies against antibiotic-resistant bacteria.

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